Sprayable surface defect detection composition and method of using same

ABSTRACT

This invention relates to a sprayable guide coat composition for use in the detection of defects on surfaces and its method of use in surface finishing processes. The composition contains anti-loading agents which improve abrasive cut and life of the abrasive article (such as sandpaper) that it is used in conjunction with. The composition also improves quality and speed of removing surface defects by providing a fast drying coating.

FIELD OF THE INVENTION

This invention relates to a sprayable guide coat composition for use inthe detection of defects on surfaces and its method of use in surfacefinishing processes. The composition contains anti-loading agents whichimprove the abrasive cut and life of the abrasive article (such assandpaper) that it is used in conjunction with. The composition alsoimproves quality and speed of removing surface defects by providing afast drying coating.

BACKGROUND OF THE INVENTION

Surface finishing processes, particularly repair processes in theautomotive refinish industry, involve the application of fillers toimperfections in the surface followed by progressive abrasion withcoarser to finer abrasive materials until the desired smooth surface isachieved. A series of protective coatings is applied, e.g., primer,sealers, base coats, clear coats, and so forth, and each layer isnormally abraded prior to application of the next coat in order toensure a smooth surface. A smooth surface is obtained by preferentiallyabrading high spots until a uniform flat aesthetically pleasing surfaceis obtained.

In order to assist the operator in identifying areas requiring abrasionand highlighting defects during the repair process, it is known to applya guide coat to the surface being abraded. The guide coats generallycomprise a dilute paint mixture which are sprayed over the surface to beabraded providing a light paint coating. As the surface is abraded, theguide coat is removed from the higher portions of the surface leavingthe visible guide coat on the lower areas. Thus, the surfaceirregularities are clearly visible to the operator, enabling theoperator to abrade and fill the appropriate areas to achieve a flat highquality repair.

Various current guide coats are applied as thin coatings of liquid paintwhich must dry or cure before the sanding operation. Aerosol paints,which are commonly thermoplastic lacquer based materials, are convenientto use and dry quickly when compared to automotive paints or primerswhen used as guide coats. However, thermoplastic materials tend to loadthe abrasive disc during the sanding operation which decreases cut rateand disc life compared to crosslinked thermoset materials. Disadvantagesof crosslinked paints or primers when used as guide coats are that theyare usually multi-component, higher solids, slower drying and lessconvenient compared to the aerosol products.

WO 95/08405 discloses a guide coat formed on a surface as part of asmoothing operation e.g., of vehicle bodywork by distributing finelydivided particulate material, e.g., a non-toxic, black powdered paintover the surface so the material remains on and thus highlights anyirregularities on the surface. The material may be wiped onto thesurface by an applicator e.g., synthetic foam or sponge impregnated withthe material. The material may be stored in a container in a loosefinely divided form or in a compact substantially solid form from whichfinely divided particles may be removed. The majority of the material issubsequently removed from the surface as this surface is abraded toremove the highlighted irregularities.

SUMMARY OF THE INVENTION

The present invention overcomes many of the disadvantages of knownaerosol and chemically crosslinked paint guide coats. The presentinvention substantially minimizes abrasive disc loading andsubstantially increases abrasive performance over the life of the disc.

The present invention provides a composition comprising:

(a) a solvent(s) having an evaporation rate of at least about 0.5 whenmeasured at a temperature of 25° C., wherein if more than one solvent isused, the solvents are miscible with each other;

(b) at least about 0.001 percent by weight of a component selected fromthe group consisting of solvent dispersible pigments, solvent solubledyes, and mixtures thereof; and

(c) at least about 1 percent by weight of an antiloading agent(s);

wherein the weight percentages are based upon the total weight of thecomposition, and wherein the composition has a Brookfield viscosity ofless than about 15,000 centipoise, and

wherein the composition is capable of drying within five minutes or lessupon coating on a substrate.

In a preferred embodiment the composition of the invention comprises:

(a) about 60 to about 99 percent by weight of a solvent(s) having anevaporation rate of at least about 0.5 to about 20 at a temperature of25 degrees C., wherein if more than one solvent is used, the solventsare miscible with each other;

(b) about 0.01 to about 20 percent by weight of a component selectedfrom the group consisting of solvent dispersible pigments, solventsoluble dyes, and mixtures thereof; and

(c) about 1 to about 50 percent by weight of an antiloading agent,

wherein the weight percentages are based upon the total weight of thecomposition, and wherein the composition has a Brookfield viscosity ofabout 10 to about 8,000 centipoise, and wherein the composition iscapable of drying within five minutes or less upon coating on asubstrate.

In an even more preferred embodiment the composition of the inventioncomprises:

(a) about 70 to about 95 percent by weight of a solvent(s) having anevaporation rate of about 3 to about 15 when measured at a temperatureof 25° C., wherein if more than one solvent is used, the solvents aremiscible with each other;

(b) about 0.1 to about 10 percent by weight of a component selected fromthe group consisting of solvent dispersible pigments, solvent solubledyes, and mixtures thereof; and

(c) about 5 to about 30 percent by weight of an antiloading agent,

wherein the weight percentages are based upon the total weight of thecomposition, and wherein the composition has a Brookfield viscosity ofabout 15 to about 5,000 centipoise, and wherein the composition iscapable of drying within five minutes or less upon coating on asubstrate.

In a most preferred embodiment the composition of the inventioncomprises:

(a) about 80 to about 90 percent by weight of a solvent(s) having anevaporation rate of about 7 to about 10 when measured at a temperatureof 25° C., wherein if more than one solvent is used, the solvents aremiscible with each other;

(b) about 0.1 to about 5 percent by weight of a component selected fromthe group consisting of solvent dispersible pigments, solvent solubledyes, and mixtures thereof;

(c) about 10 to about 20 percent by weight of an antiloading agent,

wherein the weight percentages are based upon the total weight of thecomposition, and wherein the composition has a Brookfield viscosity ofabout 20 to about 2,500 centipoise, and wherein the composition iscapable of drying within five minutes or less upon coating on asubstrate.

The present invention also provides an aerosol system comprising:

(i) a composition comprising:

(a) a solvent(s) having an evaporation rate of at least about 0.5 whenmeasured at a temperature of 25° C., wherein if more than one solvent isused, the solvents are miscible with each other;

(b) at least about 0.001 percent of a component selected from the groupconsisting of solvent dispersible pigments, solvent soluble dyes, andmixtures thereof; and

(c) at least about 1 weight percent of an antiloading agent(s);

wherein the weight percentages of (a), (b), and (c) are based upon thetotal weight of the composition, and wherein the composition has aBrookfield viscosity of less than about 15,000 centipoise, and

wherein the composition is capable of drying within five minutes or lessupon coating on a substrate;

(ii) a propellant;

wherein the composition and propellant are present in sufficient amountsand combined in such a manner as to enable the composition to be aerosolspray applied to a substrate;

wherein a coating spray applied to a substrate via the aerosol system iscapable of drying in about five minutes or less.

The present invention also provides a method of sanding a substratecomprising the steps of:

(a) providing an aerosol system comprising:

(i) a composition comprising

(A) a solvent(s) having an evaporation rate of at least about 0.5 whenmeasured at a temperature of 25° C., wherein if more than one solvent isused, the solvents are miscible with each other;

(B) at least about 0.001 percent of a component selected from the groupconsisting of solvent dispersible pigments, solvent soluble dyes, andmixtures thereof; and

(C) at least about 1 weight percent of an antiloading agent(s);

wherein the weight percentages are based upon the total weight of thecomposition, and wherein the composition has a Brookfield viscosity ofless than about 15,000 centipoise, and wherein the composition iscapable of drying within five minutes or less upon coating on asubstrate; and

(ii) a propellant;

wherein the composition and propellant are present in sufficient amountsand combined in such a manner as to enable the composition to be aerosolspray applied to a substrate;

wherein a coating spray applied to a substrate via the aerosol system iscapable of drying in about five minutes or less;

(b) spray applying a coating to a substrate to be sanded via the aerosolsystem in order to form a coated substrate;

(c) allowing the coating to dry, wherein an amount and type of componentof element (B) is present such that a color contrast visible to thenaked eye exists between the coating and the substrate to be sanded;

(d) sanding the coated substrate over the dried coating;

(e) optionally repeating steps (b) to (d) one or more times.

Preferably the substrate to be sanded is selected from the groupconsisting of putty, primer, paint, wood, metal, plastic, and gelcoat.

DETAILED DESCRIPTION OF THE INVENTION

Properties of the Composition of the Invention

The composition of the present invention can also be referred to as aconcentrate. Preferably the composition of the invention has aBrookfield viscosity of about 10 to about 8,000 centipoise, morepreferably about 15 to about 5,000 centipoise, and most preferably about20 to about 2,500 centipoise.

Preferably the composition of the invention is capable of drying inabout three minutes or less upon coating on a substrate, more preferablyin about one minute or less upon coating on a substrate, and mostpreferably about thirty seconds or less upon coating on a substrate.

Antiloading Agents

Examples of useful antiloading agent(s) which the composition cancomprise include but are not limited to those selected from the groupconsisting of metallic stearates, metallic oleates, metallic octoates,and mixtures thereof.

Examples of preferred antiloading agent(s) are those selected from thegroup consisting of zinc stearate, calcium stearate, magnesium stearate,iron stearate, copper stearate, lithium stearate, sodium stearate,strontium stearate, aluminum stearate, barium stearate, potassiumstearate, sodium oleate, aluminum octoate, and mixtures thereof Theantiloading agent zinc stearate is particularly preferred.

Preferably the composition of the invention comprises about 1 to about50 percent by weight of antiloading agent(s) based on the total weightof the composition. As antiloading agent is increased, sandingefficiency is typically improved to a point of diminishing returns.Above this point, excessive dust may be generated, cost of thecomposition can increase substantially, and the composition can becomedifficult to atomize or apply. More preferably the composition of theinvention comprises about 5 to about 30 percent by weight of antiloadingagent(s) based on the total weight of the composition. Most preferablythe composition of the invention comprises about 10 to about 20 percentby weight of antiloading agent(s) based on the total weight of thecomposition for best balance of performance, dusting minimization, cost,and delivery.

These antiloading agents help prevent sanding swarf (sanding dust) fromadhering to the surface of the coated abrasive article (such as asanding disc) used in sanding over the guide coat of the invention. Byminimizing the amount of swarf which adheres to the coated abrasivearticle, the abrasive particles' sharp edges are exposed to thesubstrate resulting in a faster cut rate and longer abrasive articlelife.

Solvent Soluble Dyes/Solvent Dispersible Pigments

The solvent soluble dye(s) selected should be soluble in the solvent(s)used according to the invention. The solvent dispersible pigment(s)selected should be dispersible in the solvent(s) used according to theinvention. With respect to the composition of the invention, preferablythe component of element (b) is a solvent soluble dye(s). Examples ofuseful specific solvent soluble dye(s) include but are not limited tothose selected from the group consisting of diphenylmethanes,triphenylmethanes, acridines, xanthenes, quinoniiines, azines, oxazines,methylene, carotinoids, carbonyl, indigo, anthraquinone, stilbene,sulfur, and mixtures thereof Examples of use solvent dispersiblepigments include but are not limited to the following: iron oxide, zincoxide, and titanium dioxide.

At very low levels of dye(s)/pigment(s), imperfections become difficultto see. At high levels the composition can become messier to apply andmore costly to produce. Preferably the composition of the inventioncomprises about 0.01 to about 20 percent by weight of a componentselected from the group consisting of solvent dispersible pigments,solvent soluble dyes, and mixtures thereof, based upon the total weightof the composition.

More preferably the composition of the invention comprises about 0.1 toabout 10 percent by weight of a component selected from the groupconsisting of solvent dispersible pigments, solvent soluble dyes, andmixtures thereof, based upon the total weight of the composition. Mostpreferably the composition of the invention comprises about 0.1 to about5 percent by weight of a component selected from the group consisting ofsolvent dispersible pigments, solvent soluble dyes, and mixturesthereof, based upon the total weight of the composition, for reasons ofeasy identification of defects while being less messy and less costly.

Solvents

The composition of the present invention comprises a solvent(s) havingan evaporation rate of at least about 0.5 when measured at a temperatureof 25° C. as measured according to American Society for Testing andMaterials (ASTM) D3539 (incorporated by reference herein), wherein ifmore than one solvent is used, the solvents are miscible with eachother. Examples of useful solvent(s) include but are not limited tothose selected from the group consisting of aliphatic hydrocarbons,aromatic hydrocarbons, chlorinated versions of the aforementioned, andmixtures thereof. Examples of preferred solvent(s) are those selectedfrom the group consisting of ketones, alcohols, esters, chlorinatedversions of the aforementioned, and mixtures thereof, for reasons ofrapid evaporation and good solvating abilities. Most preferably thesolvent(s) are selected from the group consisting of acetone,isopropanol, hexane, cyclohexane, toluene, methane, ethanol, methylethyl ketone, isobutylketone, heptane, and mixtures thereof, for reasonsof rapid evaporation, solvency, and lesser likelihood of damage to thecoated substrates.

Preferably the composition of the invention comprises about 60 to about99 percent by weight of a solvent(s) based on the total weight of thecomposition for ease of application. The higher solvent content allowseasier dispersion and delivery. More preferably the composition of theinvention comprises about 70 to about 95 percent by weight of asolvent(s) based on the total weight of the composition. Most preferablythe composition of the invention comprises about 80 to about 90 percentby weight of a solvent(s) based on the total weight of the compositionfor reasons of best delivery. When the amount of solvent is above about90 percent by weight the amount of antiloading agent present in thecomposition can become lower which can decrease the sandingeffectiveness of the abrasive article.

Preferably the solvent(s) have an evaporation rate of at least about 0.5to about 20 at a temperature of 25 degrees C. as measured according toASTM D3539 in order that the coating will dry more rapidly to avoidexcessive waiting between application and sanding.

More preferably the solvent(s) have an evaporation rate of at leastabout 3 to about 15 at a temperature of 25 degrees C. as measuredaccording to ASTM D3539. Most preferably the solvent(s) have anevaporation rate of at least about 7 to about 10 at a temperature of 25degrees C. as measured according to ASTM D3539. If the evaporation rateis too high, the composition would be applied as a messy powder due tothe solvent being evaporated before reaching the substrate during thespraying process.

Aerosol System

The level of propellant used as part of the aerosol system can vary. Ifthe propellant level is too low the propellant may not adequatelyatomize the material for uniform application. If the propellant level istoo high significant overspray onto surrounding areas can occur.Preferably the aerosol system comprises about 5 to about 50 percent byweight of the propellant, based upon the total weight of the compositionplus the propellant, more preferably about 10 to about 30 percent byweight of the propellant, based upon the total weight of the compositionplus the propellant, and most preferably about 15 to about 25 percent byweight of the propellant, based upon the total weight of the compositionplus the propellant.

Preferably the propellant is selected from the group consisting ofalkanes, alkenes, and chlorofluorocarbons and compressed gases such asnitrogen, carbon dioxide and nitrous oxide. Most preferably thepropellant is selected from the group consisting of propane andisoheptane.

The propellant can be combined with the composition according toprocedures known to those skilled in the art to form an aerosol. It maybe intermixed therewith as one example, but may instead be in a separatecompartment of a container, for example.

Binder Resins

With the present invention it is not necessary to include a binderresin. Preferably the composition of the invention comprises about 0 toabout 10 weight percent of a binder resin based on the total weight ofthe composition, more preferably about 0 to about 5 percent based uponthe total weight of the composition. Most preferably the composition isfree of binder resin.

Binder resins are materials that form a continuous film that adheres tothe substrate and holds together other substances in the coating to forma film. Known binders typically have a glass transition temperature ofless than about 100 degrees C. Examples of known binders include but arenot limited to those selected from the group consisting of acrylic,urethane, and epoxy polymers. Other examples of binders includesilicones, polyesters, polystyrene, and fluoropolymers. If binders areincluded in the present invention, they would most likely befluoropolymers or silicones.

Preparation of the Composition of the Invention

The composition of the invention can be prepared by combining thecomponents in any order. Typically, the composition of the invention isprepared by charging the solvent into a suitable vessel, followed byantiloading agent, followed by pigment(s)/dye(s), and followed by anyremaining materials. The pigment(s)/dye(s) are typically added slowly toavoid agglomeration. Agitation typically occurs throughout thepreparation process.

Method of Use of the Composition of the Invention

The composition of the invention is typically spray applied onto thesubstrate to be sanded at a distance of about 12 to about 20 inches(30.5 cm to about 50.8 cm). The composition is preferably applied to thesubstrate with smooth overlapping strokes to produce an even coating.

Surface finishing processes, particularly repair processes in theautomotive refinish industry, involve the application of fillers toimperfections in the surface followed by progressive abrasion withcoarser to finer abrasive materials until the desired smooth surface isachieved. A series of protective coatings is applied, e.g., primer,sealers, base coats, clear coats, and so forth, and each layer isnormally abraded prior to application of the next coat in order toensure a smooth surface. A smooth surface is obtained by preferentiallyabrading high spots until a uniform, flat, aesthetically pleasingsurface is obtained. As the surface is abraded the guide coat is removedfrom the higher portions of the surface leaving the visible guide coaton the lower areas. Thus, the surface irregularities are clearly visibleto the operator: enabling the operator to abrade and fill theappropriate areas to achieve a flat high quality repair.

The guide coat composition of the invention is typically applied byspraying (most typically aerosol spraying) onto the desired substrate todistribute (preferably evenly distribute) the guide coat compositionover the area to be sanded. The guide coat is allowed to dry. The areain which the guide coat has been applied can then be sanded. Upondrying, the composition is a solid dry coating with a thin layer ofpowdery residue on the surface. The composition of the invention is usedin a dry sanding process.

Preferably the substrate to be sanded is selected from the groupconsisting of putty, primer, paint, wood, metal, plastic, and gelcoat.

Test Methods

The following test methods are used herein.

Viscosity Measurement of (non-aerosol composition)

1) Use RVF Brookfield Viscometer and RV Spindles.

2) Add 400 grams of composition to a half pint can.

3) Measure viscosity of composition at 75 degrees F. (+or -2) (24° C.+or -1.2).

4) Using Spindle #1 submerge in concentrate to line. Turn on viscometerat 20 rpm. Record the number after the ₁₀ th revolution.

Multiply number by appropriate factor (5) and record viscosity incentipoise.

Dry Time Composition (Non-aerosol)

1) 4"×12" (10×31 cm) unpolished cold roll steel panels were primed withPPG Industries K-200 two component polyurethane automotive refinishprimer according to directions. The panels were cured for several weeksunder ambient conditions before testing.

2) A 5 mil (0.0127 cm) film of the concentrate was cast over the primedpanels using a square 4 inch (10.2 square cm) draw down bar #24 suppliedby Precision Gauge and Tool Company. Next, 3 grams of concentrate wasapplied onto the panel with a dropper and drawn over the primed panelwith the draw down bar. The film was allowed to volatilize at 75° F.(24° C.) without air circulation until the film was tack-free to thetouch. This time was recorded as the tack-free time.

Dry Time (Aerosol):

1) Primed panels were prepared according to the directions above.

2) The product is spray applied to the 4"×12" (10.2×30.5 cm) primedpanels at a distance of 12" from the panel by using a 50% overlapbetween passes in order to achieve a thin uniform coating. The valveused on the aerosol can was #186-27-16 supplied by Newman-Green, Inc.The film was allowed to volatilize at 75° F. (24° C.) without aircirculation until the film was tack free to the touch. This time wasrecorded as the tack-free time.

EXAMPLES

The present examples further illustrate but do not limit the presentinvention. All parts, percentages, ratios, etc. in the examples are byweight unless indicated otherwise.

Uniformity Definition:

The following uniformity definitions are used herein.

Very Good Uniformity: The atomized spray droplets are of similar sizeand coat the substrate with minimal variation in coating thickness andcolor. A continuous coating is observed.

Fair Uniformity: The atomized spray pattern is mostly small droplets ofsimilar size but also contains some larger droplets which can cause"Spitting" or "Pulsing". The resulting coating may vary in thickness andcolor intensity. The coating may not be continuous.

Poor Uniformity: The atomized spray pattern is a mixture of dropletsizes and may be difficult to dispense. The resulting coating is notcontinuous.

    ______________________________________                                        Components       Example 1 (g)                                                ______________________________________                                        Acetone          75                                                           Zinc Stearate    25                                                           Carbon Black (Elftex 8)                                                                         4                                                           Propellant       140 mls                                                      ______________________________________                                    

Preparation Procedure for Example 1:

First, 75 grams of acetone was added to a pint (473 ml) can and mixedwith a dispersator (available from Premier Mill, Temple, Pa., U.S.A.)under slow speed. Next, 25 grams of zinc stearate antiloading was slowlyadded to the acetone until a homogenous mixture was obtained (about 1minute). Next, 4 grams of carbon black pigment (Elfax 8 available fromCabot Corporation) was then added slowly to prevent agglomeration andstirred an additional 2 minutes. The mixture was then added to astandard 22 oz (650ml) aerosol can and charged with 140 milliliters ofpropane which was mixed in with the components in the can.

Spraying/Sanding Procedure I for Example 1 and Control 1

Example 1 was spray applied to a car door primed with refinish urethaneprimer (PPG K-200, available from PPG Industries) at a distance of 12inches (30.5 cm). A second such car door was left unsprayed (Control 1).Each door was sanded within 15 seconds of application using a NationalDetroit Dual Action sander with 3M STIK-IT™ Gold 320 abrasive and 3M5776 STIK-IT™ Disc Pad (both available from Minnesota Mining andManufacturing Company) at 80 psi (0.55 megapascals) line pressure.Sanding began on the door sprayed with Example 1 within 15 seconds ofapplication. Sanding results for Example 1 were then compared to thosefor Control 1 where no coating had been applied.

With respect to abrasive loading, the Control 1 abrasive disc wasapproximately 25% loaded with substrate residue as visually estimatedfrom the used abrasive disc. The Control 1 displayed 3-4 times the levelof abrasive disc loading when visually compared with the used abrasivedisc used on the coating from the Example 1 aerosol system. From theseresults it can be concluded that the use of the Example 1 compositionincreased the life of the abrasive disk.

With respect to cut rate performance, it was visually determined thatthe coating prepared from Example 1 was abrading at about 2 times therate of the Control 1 coating as indicated by the amount of substratedust removed during the abrasion process. The cut rate performance forControl 1 quickly declined as evidenced by the reduction of sanding dustand the rate at which the surface was made flat and the defects removed.

With respect to guide coat performance it was visually determined thatsurface defects were easily seen during the sanding process with Example1 that could not be visually detected when abrading the car dooraccording to Control 1. Surface defects could not be readilydistinguished for Control 1 due to the absence of any applied coloringmatter. The above results showed that abrasive loading was minimal, andcut performance improved for Example 1 when compared to the Control 1.Very good guidecoat characteristics, allowing surface defects to beeasily seen, were apparent with Example 1.

Spraying/Sanding Procedure II for Example 1 and Control 2

Example 1 was then used to quantify the increase in abrasive cut rate bysanding over basecoat/clearcoat painted panels supplied by ACT, Inc.when using the present invention compared to using no such composition(Control 2). Example 1 was first spray applied to the panel in uniformoverlapping strokes at a distance of about 12 inches (30.5 cm) to evenlycoat the panel with a thin layer of powdery residue, following theSpraying/Sanding Procedure I. Control 2 was an identical panel purchasedfrom ACT, Inc. with no composition applied thereto. The clearcoat paintwas DuPont 7103 clearcoat. A 3M STIK-IT™ Gold 320 abrasive disc wasattached to a 3M 5776 STIK-IT™ Disc Pad and was again used on a NationalDetroit Dual Action Sander at 80 psi (0.55 megapascals).

The panels were weighed initially and then again after each of five 30second sanding procedures to determine the aggressiveness and life ofthe abrasive by measuring the difference in weight of the panels. Thisdifference is an indication of how much paint was removed and isconsidered a measurement of abrasive cut rate or aggressiveness.

The Example 1 material was reapplied to the panel between each weighingby spray applying one coat of the aerosol composition at a distance ofabout 12 inches (30.5 cm) to uniformly coat the substrate surface. ForControl 2, no composition was applied to the panel prior to or betweensanding operations to simulate normal abrasive performance and sandingprocedures.

    ______________________________________                                                 Panel Weight Difference                                                                       Panel Weight Difference                              Sanding Step                                                                           for Example 1 (grams)                                                                         for Control 2 (grams)                                ______________________________________                                        lst      2.75            2.4                                                  2nd      2.04            1.48                                                 3rd      1.8             0.88                                                 4th      1.5             0.62                                                 5th      1.68            0.54                                                 ______________________________________                                    

Preparation, Spraying and Sanding/Examples 2, 3, and 4

Examples 2, 3, 4 were prepared using the same method as in thepreparation of Example 1. First, the acetone was added to a pint (473ml) can and mixed with a dispersator (available from Premier Mill,Temple, Pa., U.S.A.) under slow speed. Next, the zinc stearate wasslowly added to the acetone until a homogeneous mixture was obtained(about 1 minute). Next the pigment was added slowly to preventagglomeration and stirred an additional 2 minutes. The mixture was thenadded to a standard 22 oz (650 ml) aerosol can and charged withpropellant which was intermixed with the other components in the can.The level of propane propellant was varied to help determine an optimumlevel for spray pattern uniformity and dry time.

    ______________________________________                                                 Example 2 (g)                                                                          Example 3 (g)                                                                            Example 4 (g)                                    ______________________________________                                        Acetone    80         80         80                                           Dye (Rose Bengale)                                                                       0.75       0.75       0.75                                         Zinc Stearate                                                                            20         20         20                                           Propane Propellant                                                                       50 mls     100 mls    150 mls                                      ______________________________________                                    

The procedure of Example 1 was followed when preparing the aerosolsystems of Examples 2, 3, and 4, except for substitution of the dye typeand component amounts.

The spraying/sanding procedure used was the same as that for Example 1.The samples were spray applied to a car door primed with refinishurethane primer that had been allowed to cure for several days (PPGK-200, available from PPG Industries) at a distance of about 12 inches(30.5 cm). A second such primed car door was left unsprayed (Control 1).Each door was sanded within 15 seconds of application using a NationalDetroit Dual Action sander with 3M STIK-IT™ Gold 320 abrasive and 3M5776 STIK-IT™ Disc Pad (both available from Minnesota Mining andManufacturing Company) at 80 psi (0.55 MPA) line pressure. Sanding beganon the doors sprayed with Examples 2, 3, and 4 within 15 seconds ofapplication. Sanding results for Examples 2, 3 and 4 were then comparedto those for Control 1 where no coating had been applied.

The abrasive cut rate for Example 2 was the same as in Example 1. It wasvisually determined that the disk used with Example 2 was abrading atabout 2 times the rate of the disk used with Control 1 as indicated bythe amount of substrate dust removed during the abrasion process.

The uniformity for Example 2 was fair as determined by visualobservation. The atomized spray pattern was mostly small droplets ofsimilar size but also contained some larger droplets which caused"Spitting" and "Pulsing". The resulting coating varied in thickness andcolor intensity. The coating was not continuous.

The dry time for Example 2 was very good as determined by the coatingbeing dry to the touch within 30 seconds from it being applied and readyfor the sanding operation.

It was visually determined that the disk used with Example 3 wasabrading at about 2 times the rate of the control as indicated by theamount of substrate dust removed during the abrasion process.

The uniformity for the Example 3 coating was very good as determinedvisually. The atomized spray droplets were of similar size and coatedthe substrate with minimal variation in coating thickness and color. Acontinuous coating was observed.

The dry time for Example 3 was very good as determined by the coatingbeing dry to the touch within 30 seconds from it being applied and readyfor the sanding operation.

It was visually determined that Example 4 was abrading at about 2 timesthe rate of the Control 1 as indicated by the amount of substrate dustremoved during the abrasion process.

The uniformity for Example 4 was very good as determined visually. Theatomized spray droplets were of similar size and coated the substratewith minimal variation in coating thickness and color. A continuouscoating was observed.

The dry time for Example 4 was very good as determined by the coatingbeing dry to the touch within 30 seconds from it being applied and readyfor the sanding operation.

Rose Bengale was a bright distinguishing color that improved visualidentification of defects compared to carbon black of Example 2.

Preparation/Spraying/Sanding Procedure for Examples 5 and 6

Example 5 was prepared by first combining 100 grams of Example 2 (priorto adding propellant to Example 2) with 100 grams of acetone. Next, 200grams of the mixture was added to a 22 oz (650 ml) aerosol can andcharged with 150 mls of propane propellant.

Example 6 was prepared by combining 100 grams of Example 2 (prior toadding propellant to Example 2) with 100 grams of isopropanol. 200 gramsof the mixture was added to a 22 oz (650 ml) aerosol can and chargedwith 150 mls of propellant.

Example 5 and 6 were each spray applied as in Examples 2, 3, and 4 to acar door primed with refinish urethane primer that had been allowed tocure for several days (PPG K-200, available from PPG Industries) at adistance of about 12 inches (30.5 cm). An additional car door was leftunsprayed (Control 1). Each door was sanded within 15 seconds ofapplication using a National Detroit Dual Action sander with 3M STIK-IT™Gold 320 abrasive and 3M 5776 STIK-IT™ Disc Pad (both available fromMinnesota Mining and Manufacturing Company) at 80 psi (0.55 megapascals)line pressure.

Examples 5 and 6 displayed good sanding properties and guide coatcharacteristics with a lower level of airborne stearate dust than forExamples 2, 3, and 4, by visual observations. Both Examples 5 and 6 hadgood dry times and uniformity. (It was thought that Example 5 may drytoo fast and so isopropanol was used in place of acetone due to itsslower evaporation rate). Example 6 was preferred over Example 5 due toits combination of uniform spray application and drying time.

    ______________________________________                                                    Example 5 (g)                                                                          Example 6 (g)                                            ______________________________________                                        Example 2     100        100                                                  Acetone       100        0                                                    Isopropanol   0          100                                                  ______________________________________                                    

It was visually determined that Example 5 was abrading at about 2 timesthe rate of the Control 1 as indicated by the amount of substrate dustremoved during the abrasion process.

The uniformity for Example 5 was Fair. The atomized spray pattern wasmostly small droplets of similar size but also contained some largerdroplets which caused "Spitting" and "Pulsing". The resulting coatingvaried in thickness and color intensity thickness and color. Acontinuous coating was observed.

The dry time for Example 5 was very good as determined by the coatingbeing dry to the touch within 30 seconds from it being applied and readyfor the sanding operation.

It was visually determined that Example 6 was abrading at about 2 timesthe rate of the Control 1 as indicated by the amount of substrate dustremoved during the abrasion process.

The uniformity for Example 6 was Very Good. The atomized spray dropletswere of similar size and coated the substrate with minimal variation incoating thickness and color. A continuous coating was observed.

The dry time for Example 6 was very good as determined by the coatingbeing dry to the touch within 30 seconds from it being applied and readyfor the sanding operation.

The effect of Example 6 on the sanding efficiency of three differentgrades of abrasive paper was determined. Example 6 was used to quantifythe increase in abrasive cut rate by sanding over basecoat/clearcoatpainted panels supplied by ACT, Inc. The clearcoat paint was DuPont 7103clearcoat. 3M STIK-IT™ Gold 320 abrasive and a 3M 5776 STIK-IT™ Disc Padwere used on a National Detroit Dual Action Sander at 80 psi. (0.55megapascals).

The panels were weighed initially and then again after each 30 secondsanding procedure to determine the aggressiveness and life of theabrasive by measuring the difference in weight of the substrate. Thesevalues are recorded below along with the total amount of paint removedafter 5 applications.

    ______________________________________                                        Grams Removed Per Sanding Step                                                                                            Total                             Abrasive                                    Grams                             Grade   Example 6                                                                              1.sup.st                                                                             2.sup.nd                                                                           3.sup.rd                                                                           4.sup.th                                                                           5.sup.th                                                                           Removed                           ______________________________________                                        80 Grade                                                                              Yes      3.44   3.65 3.62 3.4  3.77 17.88                                     No       2.86   3.19 3.08 3.02 3.03 15.18                             320 Grade                                                                             Yes      2.67   2.07 1.79 1.61 1.51 9.65                                      No       2.31   1.42 0.89 0.63 0.46 5.71                              1000 Grade                                                                            Yes      0.66   0.49 0.3  0.21 0.17 1.83                                      No       0.44   0.28 0.14 0.13 0.08 1.07                              ______________________________________                                    

The data in the table above demonstrate the dramatic increase inabrasive cut rate leading to significant time savings in achieving adefect-free flat finish. It also shows that abrasive disc life isextended leading to lower cost of abrasion operations.

In the table above, "yes" means that the inventive composition wasapplied to each of the individual panels between each weight measurementand sanding procedure to determine if abrasive cut and life wereimproved. "No" means that the composition was not used with a similarpanel between sanding to demonstrate the abrasive performance withoutthe inventive composition.

Various modifications and alterations of this invention will becomeapparent to those skilled in the art without departing from the scopeand spirit of this invention, and it should be understood that thisinvention is not to be unduly limited to illustrative embodiments setforth herein.

It is claimed:
 1. A composition comprising:(a) a solvent(s) having anevaporation rate of at least about 0.5 when measured at a temperature of25° C., wherein if more than one solvent is used, the solvents aremiscible with each other; (b) at least about 0.001 percent by weight ofa component selected from the group consisting of solvent dispersiblepigments, solvent soluble dyes, and mixtures thereof; and (c) at leastabout 1 percent by weight of an antiloading agent(s); wherein the weightpercentages are based upon the total weight of the composition, andwherein the composition has a Brookfield viscosity of less than about15,000 centipoise, and wherein the composition is capable of dryingwithin five minutes or less upon coating on a substrate.
 2. Thecomposition of claim 1 which comprises about 0 to about 10 weightpercent of a binder resins based on the total weight of the composition.3. The composition of claim 1 which is free of binder resin.
 4. Thecomposition of claim 1 wherein the composition has a Brookfieldviscosity of about 10 to about 8,000 centipoise.
 5. The composition ofclaim 1 wherein the composition has a Brookfield viscosity of about 15to about 5,000 centipoise.
 6. The composition of claim 1 wherein thecomposition has a Brookfield viscosity of about 20 to about 2,500centipoise.
 7. The composition of claim 1 which is capable of drying inabout three minutes or less upon coating on a substrate.
 8. Thecomposition of claim 1 which is capable of drying in about one minute orless upon coating on a substrate.
 9. The composition of claim 1 which iscapable of drying in about thirty seconds or less upon coating on asubstrate.
 10. The composition of claim 1 wherein the antiloadingagent(s) is selected from the group consisting of metallic stearates,metallic oleates, metallic octoates, and mixtures thereof.
 11. Thecomposition of claim 1 wherein the antiloading agent(s) is selected fromthe group consisting of zinc stearate, calcium stearate, magnesiumstearate, iron stearate, copper stearate, lithium stearate, sodiumstearate, strontium stearate, aluminum stearate, barium stearate,potassium stearate, sodium oleate, aluminum octoate, and mixturesthereof.
 12. The composition of claim 1 wherein the antiloading agent iszinc stearate.
 13. The composition of claim 1 wherein the component of(b) is a solvent soluble dye(s).
 14. The composition of claim 1 whereinthe solvent soluble dye(s) is selected from the group consisting ofdiphenylmethanes, triphenylmethanes, acridines, xanthenes, quinonimines,azines, oxazines, methylene, carotinoids, carbonyl, indigo,anthraquinone, stilbene, sulfur, and mixtures thereof.
 15. Thecomposition of claim 1 wherein the solvent(s) is selected from the groupconsisting of aliphatic hydrocarbons, aromatic hydrocarbons, chlorinatedversions of the aforementioned, and mixtures thereof.
 16. Thecomposition of claim 1 wherein the solvent(s) is selected from the groupconsisting of ketones, alcohols, esters, chlorinated versions of theaforementioned, and mixtures thereof.
 17. The composition of claim 1wherein the solvent(s) is selected from the group consisting of acetone,isopropanol, hexane, cyclohexane, toluene, methane, ethanol, methylethyl ketone, isobutylketone, heptane, and mixtures thereof.
 18. Acomposition comprising:(a) about 60 to about 99 percent by weight of asolvent(s) having an evaporation rate of at least about 0.5 to about 20at a temperature of 25 degrees C., wherein if more than one solvent isused, the solvents are miscible with each other; (b) about 0.01 to about20 percent by weight of a component selected from the group consistingof solvent dispersible pigments, solvent soluble dyes, and mixturesthereof; and (c) about 1 to about 50 percent by weight of an antiloadingagent, wherein the weight percentages are based upon the total weight ofthe composition, and wherein the composition has a Brookfield viscosityof about 10 to about 8,000 centipoise, and wherein the composition iscapable of drying within five minutes or less upon coating on asubstrate.
 19. A composition comprising:(a) about 70 to about 95 percentby weight of a solvent(s) having an evaporation rate of about 3 to about15 when measured at a temperature of 25° C., wherein if more than onesolvent is used, the solvents are miscible with each other; (b) about0.1 to about 10 percent by weight of a component selected from the groupconsisting of solvent dispersible pigments, solvent soluble dyes, andmixtures thereof; and (c) about 5 to about 30 percent by weight of anantiloading agent, wherein the weight percentages are based upon thetotal weight of the composition, and wherein the composition has aBrookfield viscosity of about 15 to about 5,000 centipoise, and whereinthe composition is capable of drying within five minutes or less uponcoating on a substrate.
 20. A composition comprising:(a) about 80 toabout 90 percent by weight of a solvent(s) having an evaporation rate ofabout 7 to about 10 when measured at a temperature of 25° C., wherein ifmore than one solvent is used, the solvents are miscible with eachother; (b) about 0.1 to about 5 percent by weight of a componentselected from the group consisting of solvent dispersible pigments,solvent soluble dyes, and mixtures thereof; (c) about 10 to about 20percent by weight of an antiloading agent, wherein the weightpercentages are based upon the total weight of the composition, andwherein the composition has a Brookfield viscosity of about 20 to about2,500 centipoise, and wherein the composition is capable of dryingwithin five minutes or less upon coating on a substrate.